In the related art, there is a known image-acquisition system with which a target region is set on a low-resolution overall specimen image, for example, a map image, and then, a high-resolution image of the target region is acquired (for example, see Patent Literature 1).
In the case in which a portion of a region of a specimen needs to be observed in a greater detail, there is a problem in that acquiring a high-resolution overall specimen image increases the amount of time required to acquire the image, and the volume of image data is also increased. With the image-acquisition system described in Patent Literature 1, the overall specimen image is acquired at a low resolution, and the image of the target region is acquired at a high resolution, thus decreasing the amount of time required to acquire an image and decreasing the volume of the image data.